VARIANTS WITHIN THE 5'-FLANKING REGION AND THE INTRON-I OF THE BOVINEGROWTH-HORMONE GENE

In order to identify DNA variants potentially involved in the regulati on of the expression of the bovine growth hormone gene, the 5'-flankin g, the 5'-untranslated and the signal peptide coding regions of 15 cow s (four German Friesian, two German Simmental, two Jersey, two Gallowa y, two Scottish Highland, two Charolais and one Ceylon Dwarf Zebu) wer e analysed. For each animal a region of about 1 . 2 kb was amplified b y polymerase chain reaction (PCR) and sequenced, Six sites of variable nucleotides were identified in the 5'-flanking region of the gene and one in the intron I. Some of these variable sites are also potential binding sites for trans-acting factors (CAAT/enhancer binding protein (C/EBP), polyoma virus enhancer A binding protein 3 (PEA3), thyrcid ho rmone response element (TRE)) and therefore possibly involved in the e xpression of the growth hormone gene. PCR amplification of specific al leles (PASA) tests for two of the sites (G2, G3) were established and the genotypes for these variants were analysed in 190 cows. The freque ncies of the C alleles of the sites G2 and G3 were 0 . 63 and 0 . 76, respectively.